Biological indicator testing procedure

The biological indicator (spore testing) procedure is a critical method to confirm sterilization effectiveness. This is particularly important in autoclaves and other sterilizers.

This procedure uses biological indicators (BIs) containing highly resistant spores of microorganisms (e.g., Geobacillus stearothermophilus for steam sterilization or Bacillus atrophaeus for dry heat or ethylene oxide sterilization).

Materials Needed for testing procedure

• Biological indicators (self-contained spore vials or strips with spores).
• Sterilization equipment (e.g., autoclave, dry heat sterilizer, or gas sterilizer).
• Sterile forceps (if required to handle spore strips).
• Incubator or testing system specific to the biological indicator being used.
• Control biological indicator (unprocessed BI for comparison).
• Personal Protective Equipment (PPE).

Biological indicator spore testing procedure

1. Check the manufacturer’s guidelines for the specific biological indicator being used.
2. Place the biological indicators in the most challenging location for sterilization (e.g., center of a pack, near the sterilizer’s cold spot).
3. Use one biological indicators per load, along with routine mechanical and chemical monitoring (e.g., tape indicators).
   • NOTE: Keep one biological indicator from the same lot unprocessed to act as a control.
4. Load the sterilizer and run the cycle according to validated settings (e.g., temperature, pressure, and duration).
5. Once the cycle is finished and the load is cooled, carefully remove the processed BI from the sterilizer. Use a sterile or clean technique for removal.
6. Place both the processed BIs and control BIs in an incubator. Set it at the recommended temperature. Keep them there for the specified duration, typically 48 hours.
   • Most BIs for steam sterilization incubate at 55-60°C, while dry heat sterilization BIs incubate at 30-37°C.
7. After incubation, check the processed and control BIs for color changes, turbidity, or other signs of microbial growth:
   • Processed BI: No growth indicates sterilization was successful.
   • Control BI: Must show growth to confirm that the spores were usable.
8. If the processed BI shows growth (indicating sterilization failure):
   • Promptly stop using the sterilizer.
   • Re-run the sterilizer with another BI to confirm results.

Frequency of Spore Testing

• Perform spore testing at least weekly.
• Test every load containing implantable devices, with results verified before use.
• Test sterilizers after repairs, relocation, or major maintenance.

Key Considerations

• Follow the manufacturer’s instructions for both the sterilizer and the biological indicator.
• Ensure proper storage and handling of biological indicators to avoid contamination or expiration.
• Maintain a sterilization log for regulatory compliance and quality assurance.

Let me know if you’d like additional clarification or assistance with documentation templates for this process!